Funds are requested for an Epics 742 flow cytometer to be shared by a group of 13 investigators engaged in 14 projects at the Duke University Medical Center. Availability of the analytical and sorting capabilities of this machine would facilitate both clinical and laboratory investigation in a number of areas including: the immunodiagnosis of ovarian carcinoma, immunodetection of bone marrow metastases, analysis of tumor-host interactions, characterization of tumor cell heterogeneity, mechanisms of drug resistance, serotherapy of murine leukemia, mechanisms of monocyte chemotaxis, pathogenesis of AIDS, and regulation of myeloid and lymphoid differentiation. In completing these studies, investigator's would utilize different features of the Epics 742 1) to perform multiparameter phenotypic analysis and sorting, 2) to study marker expression during different phases of the cell cycle, and 3) to clone individual hybridomas, T cells and tumor cells.